TUTORIAL #7
Using the Smith Chart
1. [2.19 P expanded] Use the Smith chart to find the following quantities for the transmission-line
circuit in the figure below.
L 0.4
Z 0 50
(a)
(b)
(c)
(d)
(e)
(f)
Z L 60 j 50
Z in
The SWR on the line.
The reflection
The following is the equation solving the circuit shown below:
f ( x) 5 10 15 e x / 0.026 x 2
The function is plotted below.
We can observe from the graph that the root is near (4 sig fig)
There are five different methods to determine the roots more accur
BODE PLOTS IN MATLAB
Examples using three different methods applied to the transfer function from Prelab 1:
TF =
20000 s + 20000
Method 1: Easiest (If you have the Control Toolbox in Matlab)
s=tf('s'); H = (20000/(s+20000); Bode(H) grid on
Method 2: Annal
Measuring Input and Output
Impedance
H om e
Simulation
Analysis
Updates
H e lp
Media
Links
Practical
Schematics
Art i cl e : Andy Collinson
Emai l me
Input Impedance
Met er Met hod
From the AC impedance triangle, the input or output impedance
of a two ter
ELEC 356 Electronics II Amplifier Frequency Response
BJT Amplifier Frequency Response
Bandwidth of an Amplifier
Most amplifiers have relatively constant gain over a certain range (band) of frequencies, this is called
the bandwidth (BW) of the amplifier.
F
Lecture 280 Series-Shunt and Shunt-Series Feedback (3/15/02)
Page 280-1
LECTURE 280 SERIES-SHUNT AND SHUNT-SERIES FEEDBACK
(READING: GHLM 579-587) Objective The objective of this presentation is: 1.) Illustrate the analysis of series-shunt and shunt-serie
General Frequency Considerations
Frequency response of an amplifier refers to the frequency range in which the amplifier
will operate with negligible effects from capacitors and capacitance in devices.
This range of frequencies can be called the mid-range
The Fourier Transform
As we have seen, any (sufficiently smooth) function f (t) that is periodic can be built out of sin's and cos's. We have also seen that complex exponentials may be used in place of sin's and cos's. We shall now use complex exponential
c
Copyright 2009. W. Marshall Leach, Jr., Professor, Georgia Institute of Technology, School of
Electrical and Computer Engineering.
Feedback Ampliers
Collection of Solved Problems
A collection of solved feedback amplier problems can be found at the belo
Section F8: Summary
No matter how great your amplification system is, if you cant get what you
need where you need it, its not worth a lot. What weve (hopefully)
accomplished in this section of our studies is to introduce the power
amplifier the output st
Section F7: Switching Regulators
In the previous section, we discussed discrete and selected IC regulators.
Although these regulators are easily set up and extremely useful, they suffer
from several limitations. The most serious limitation has to do with
Section F6: Power Supply Using Power Transistors
In this section of our studies we will be looking at the design of power
supplies using power transistors. We discussed the concepts of rectification
and filtering using regular and zener diodes in Section
Section F5: Darlington Circuit
To provide improved performance and input/output
characteristics, single transistors may be combined
to form compound devices. A commonly used
compound device is known as the Darlington
configuration and is shown to the righ
Section F4: Power Amplifier Circuits - Class B & AB
Recall that the Class B amplifier was also
referred
to
as
a
push-pull
(or
complementary symmetry) configuration,
where one transistor is used to amplify the
positive portion of the input signal and a
sec
Section F
Power Amplifiers and Power Supplies
(Chapter 8 of your text)
Section F1: Introduction & Goals
An amplification system may consist of several stages created by one or
more of the single-stage amplifier configurations we have been studying.
Many t
UNIVERSITY OF CALIFORNIA AT BERKELEY College of Engineering Department of Electrical Engineering and Computer Sciences Discussion Notes #9 EE 105 Prof. Wu Spring 2007
1
BJT Ampliers
Recall from Chapter 7 our discussion of MOSFET ampliers: common-source, c
6. Frequency Response
Reading: Sedra & Smith: Chapter 1.6, Chapter 3.6
and Chapter 9 (MOS portions),
ECE 102, Winter 2011, F. Najmabadi
Typical Frequency response of an Amplifier
Up to now we have ignored the capacitors. To include the capacitors, we
nee
VI. Transistor ampliers: Biasing and Small Signal Model
6.1 Introduction
Transistor ampliers utilizing BJT or FET are similar in design and analysis. Accordingly we will discuss BJT ampliers thoroughly. Then, similar FET circuits are briey reviewed. Consi
Feedback Amplifier Stability
A() ) Ao Afo
* Feedback analysis
h
Midband gain with feedback A = fo New low and high 3dB frequencies
Hf = 1 + f Ao H
Ao 1 + f Ao
h
(
)
Lf =
h
Modified input and output resistances, e.g.
Rif =
(
L 1 + f Ao
)
(
Ri 1 + f AIo '
Shunt-Series Feedback Amplifier - Ideal Case
*
Current feedback
Current sampling
Feedback circuit does not load down the basic
amplifier A, i.e. doesnt change its characteristics
Doesnt change gain A
Doesnt change pole frequencies of basic
amplifier A
Shunt-Shunt Feedback Amplifier - Ideal Case
*
*
For this configuration, the appropriate gain is the
TRANSRESISTANCE GAIN A = ARo = Vo/Ii
*
For the feedback amplifier as a whole, feedback changes
midband transresistance gain from ARo to ARfo
ARo
ARfo =
1 +
Series-Series Feedback Amplifier - Ideal Case
Voltage fedback
to input
*
Feedback circuit does not load down the basic
amplifier A, i.e. doesnt change its characteristics
Doesnt change gain A
Doesnt change pole frequencies of basic
amplifier A
Doesnt c
Feedback
Xs
+
Xi
Xo
Xf
f
* What is feedback?
Taking a portion of the signal arriving at the
load
and
feeding it back to the input.
* What is negative feedback?
Adding the feedback signal to the input so as to
partially cancel the input signal to the ampli
Comparison of Amplifier Configurations
Midband Characteristics*
These are approximate expressions neglecting the effects of the biasing resistors R 1 and R2
and the source resistance RS.
J. Millman and A. Grabel, Microelectronics, 2nd Ed., McGraw Hill, N
Emitter-Follower (EF) Amplifier
* DC biasing
C B CE
Calculate I , I , V Determine related small signal equivalent circuit parameters m h Transconductance g h
* * High and Low Frequency AC Equivalent Circuit
Input resistance r Midband gain analysis Low f